Michael Addison was sentenced to die for killing Manchester Police Officer Michael Briggs. The court previously found that the sentence was constitutional, but the question before the court Thursday was whether the sentence was too harsh.

Because New Hampshire hasn't executed anyone since 1939, the pool of cases where someone has been sentenced to die in the state is practically nonexistent. The defense and prosecution cited cases from other jurisdictions while acknowledging that the death penalty in New Hampshire differs from other states.

"This review is unique because there is no other situation in which I can conceive in which this court would consider vacating a jury verdict," said defense attorney David Rothstein.

Addison shot and killed Briggs in 2006. The defense argued that the death sentence imposed by the jury was too harsh, saying that factors considered in other states that impose the death penalty are missing in this case

"The jury did not find substantial planning or premeditation before the murder, did not find the purpose to kill, did not find the defendant a future danger," Rothstein said.

In order to make its case, the defense submitted more than 350 cases for the court to consider, while the state said the court should look at 12 cases. The justices seemed concerned about the small number of cases submitted by the state.

"So, I'm feeling a little uncomfortable with making the decision as to whether death in this case was aberrant by looking at only 12 cases," said Justice Carol Ann Conboy.

The state countered by saying that while the defense cited more cases, those cases weren't similar to the law in New Hampshire.

"In all those other states that the defendant talked about, this defendant couldn't even be convicted of capital murder in those states," said Senior Assistant Attorney General Jeff Strelzin.

Briggs' wife and parents attended the court session but would not comment. Also present was a small group of protesters who are opposed to the death penalty.